24 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



2. Panicum utowanaeum Scribn. 



Panicum utowanaeum Scribn. in Millsp. Field Columb. Mus. Bot. 2 : 25. 1900. 

 "No. 702 [Millspaugh Plant. Utowan.], from a dry hillside near Guanica, Porto Rico, 

 Jan. 22, 1899. Type in Field Col. Mus. Herb. No. 60702. " In this specimen the root- 

 stock is scarcely visible, but in the duplicate in the National Herbarium the slender 

 rootstock is shown. 



Panicum sintenisii Nash, Bull. Torrey Club 30 : 382. 1903. "In woods, Guanica, 

 Sintenis 3463." The type, in the herbarium of the New York Botanical Garden, is 

 labeled "Guanica, in sylva ad Cerro de la Ensenada, Porto Rico. Sintenis 3463, Jan. 

 28, 1886." The specimen shows only a trace of the slender rootstock. 



DESCRIPTION. 



Plants tufted from the joints of short, slender rootstocks, glabrous; culms ascend- 

 ing or somewhat spreading, 25 to 60 cm. high, slender, compressed, sparingly 

 branching; sheaths shorter than the internodes, compressed, especially the lower- 

 most, ciliate at the auriculate summit; ligule a minute ring of* stiff hairs; blades erect 

 or spreading above, 10 to 20 cm. long, 1 to 4 mm. wide, slightly scabrous on the margin 

 (sometimes sparsely pilose on the upper surface at the base), 

 narrowed and more or less involute at the base and much nar- 

 rower than the sheath; panicles 3 to 10 cm. long, very slender, 

 the scattered, erect branches 1 to 3 cm. long, the bristle usu- 

 ally equaling or exceeding the spikelet; spikelets subsessile, 

 2 to 2.1 mm. long, 0.6 to 0.7 mm. wide, elliptic, somewhat 

 beaked at the summit, glabrous, pale with green nerves; first 

 glume half as long as the spikelet, acute, 3-nerved; second 

 glume two-thirds to three-fourths as long as the fruit, 3 to 5- 

 Fig. 2.-P. utowanaeum. nerved, sterile lemma 5-nerved, abruptly pointed; fruit 1.9 

 From type specimen. mm. long, 0.6 mm. wide, elliptic, minutely rugose; slightly 



beaked at the acute apex. 

 This species is closely allied to P. distantiflorum, but may be distinguished from it 

 by the wider, flat or scarcely involute blades and larger, pale, less strongly nerved 

 spikelets. The rootstock is very slender and so easily broken off in collecting that 

 only about half the specimens cited below show it. 



DISTRIBUTION. 



Open rocky soil, mostly near the coast, Cuba, Porto Rico, and Guadeloupe. 

 Cuba: Triscornia, near Habana, Hitchcock 141, Tracy 9089; without locality, 



Wright 3452 (Gray Herb.). 

 Porto Rico: Guanica, Millspaugh PI. Utow. 702, Sintenis 3365, 3416, 3463 (N. Y. 



Bot. Gard. Herb.). 

 Leeward Islands: Guadeloupe, Duss 3177. 



3. Panicum chapmani Vasey. 



Panicum chapmani Vasey, Bull. Torrey Club 11 : 61. 1884. No locality nor speci- 

 men is cited, but the author says: "This is the Panicum tenuiculmum of Chapman's 

 Flora, but is not the P. tenuiculmum of Meyer." A specimen in the National Herba- 

 rium from the Chapman Herbarium labeled "Panicum tenuiculmum S. Fl. S. Florida " 

 in Chapman's hand, and "Panicum Chapmani Vasey," in Vasey's hand, is chosen as 

 the type. 



